<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Demo3.7</title>
    <style>
        .classA{color: red;}
    </style>
</head>
<body>
    <script src="/js/vue.js"></script>
    <div id="app">
       <div v-bind:class="{'classA':isRed}">我是v-bind指令,绑定class属性</div>
       <div v-bind:style="{'fontSize':size+'px'}">我是v-bind指令,绑定style属性</div>
    </div>
</body>
    <script>
      let vm = new Vue({
        el:"#app",
        data:{ 
          isRed:true,
          size:20
        }
    })
    </script>
</html>